Birth Defects

What is a birth defect?

A birth defect is a structural or metabolic abnormality most often present at birth or identified prenatally (before birth).

Structural birth defects involve a body part or organ that is malformed or missing.

Metabolic (or biochemical) birth defects involve problems with controlling the body’s chemistry or producing enough of a certain protein.

While most birth defects are noticed at birth, certain birth defects (such as a small heart defect or autism) cannot be detected until a child is older.


What causes birth defects?

  • Unfortunately, approximately 70% of all birth defects do not have a known cause.
  • Only 10% of birth defects have a known genetic cause. These birth defects may be inherited (passed from parent to child).
  • The remaining 20% of birth defects are caused by a baby’s exposure to a teratogen. A teratogen is any substance that disrupts the normal development of a baby. 

    There are four categories of teratogens:

      1. Recreational drugs (alcohol, tobacco, marijuana, cocaine, and other drugs)
      2. Prescription or over-the-counter medications (such as thalidomide, retinoic acid, and warfarin)
      3. Environmental exposures (lead, radiation, pesticides)
      4. Infectious diseases or other health-related conditions (cytomegalovirus (CMV), rubella, chicken pox, syphilis, diabetes, phenylketonuria (PKU), obesity)

    **If you have questions or concerns regarding teratogens, please contact the Indiana Teratogen
    Information Service at (317) 274-1071.**

    Prevention of Birth Defects

    While the causes of most birth defects have not yet been identified, there are several things that women can do to help ensure that Indiana’s babies are as healthy as possible. These include:

    • Take a multivitamin each day that contains 400 micrograms (mcg) of folic acid. Folic acid has been shown to decrease the chance that a baby will be born with a neural tube defect (such as spina bifida).
    • Avoid teratogens.
    • Get early prenatal care, and go to every appointment.
    • Have regular medical check-ups.
    • Keep vaccinations (shots) up-to-date.
    • Eat a healthy, balanced diet. Avoid eating raw or undercooked meat.
    • Talk with your health care provider about any medicine (prescription or over-the-counter) you are taking.
    • Talk with your health care provider about your home and work environments.
    • Talk with your health care provider about any medical problems or concerns you have.
    • Keep up these healthy habits while pregnant!

    Many birth defects happen very early in a pregnancy—sometimes even before a woman knows that she is pregnant. Following healthy habits gives women the best chance to have healthy babies.


    For a list of resources for families of children with a birth defect, please click here.  For help before, during, or after pregnancy, please call the Indiana Family Helpline at (800) 433-0746.



    For more information on a specific birth defect, please click on the name of the birth defect below.


    Congenital heart defects Other Birth Defects
    Aortic valve stenosis (en español) Anencephaly 
    Atrial septal defect (ASD) (en español) Aniridia (en español)
    Coarctation of the aorta (en español) Anophthalmia (en español)
    Ebstein’s anomaly (en español) Anotia (en español)
    Endocardial cushion defects (en español) Bladder exstrophy (en español)
    Hypoplastic left heart syndrome (HLHS) (en español) Congenital cataracts (en español)
    Patent ductus arteriosus (PDA) (en español) Cleft lip and cleft palate (en español)
    Pulmonary valve atresia (en español) Diaphragmatic hernia (en español)
    Pulmonary stenosis (en español) Congenital hip dislocation (en español)
    Tetralogy of Fallot (TOF) (en español) Down syndrome (en español)
    Transposition of the great arteries / vessels (TGA/TGV) (en español) Encephalocele (en español)
    Truncus arteriosus (en español) Esophageal atresia (en español)
    Tricuspid valve atresia (en español) Gastroschisis (en español)
    Ventricular septal defect (VSD) (en español) Hirschsprung’s disease (en español)
      Hydrocephalus (en español)
      Hypospadias (en español)
      Intestinal atresia (en español)
      Microcephaly (en español)
      Omphalocele (en español)
      Pyloric stenosis
      Renal agenesis (en español)
      Spina bifida (en español)